Whether they're running 19 mph down a track or dunking in a basketball game, athletes are the closest thing we have to real-life superheroes. We asked four of our favorites what unique power has helped them become champions, as well as the moves that keep them powered up.

Dawn Harper-Nelson

"I visualize the first eight steps of a race for hours beforehand, trying to get them just right in my head," says Dawn Harper-Nelson, who will run the 100-meter hurdles in Rio. That total commitment to precision—plus a smooth stride powered by superstrong glutes and legs—helps her clear hurdles at breakneck pace. And the track star knows firsthand how crucial each micro-moment is for a podium finish: She missed the gold medal in London in 2012 by a mere 0.02 second. Her attention to detail started young. "My mom used to call me inside as it was getting dark, and I'd beg to practice more," says the self- described perfectionist. "Then I'd come in and hurdle the arm of the couch!"

Her Moves

Improving as a sprinter involves more than running. Harper-Nelson shares her plyometric drills for a speedier stride.

1. High Knees Run in place, bringing knees to chest as high as possible while pumping arms, landing on balls of feet. Keep chest lifted throughout. Continue for 30 seconds. Rest 30 seconds. Repeat twice.

4. Pause Squat Stand with feet hip-width apart, toes out. Keep chest up and back straight as you squat with knees over ankles until thighs are parallel to floor. Pause 10 seconds. Return to start for 1 rep. Do 3 sets of 10 reps.

Gevvie Stone

There's a beautifully rhythmic cadence to rowing: Lean forward, catch the blade in the water, push through your heels and pull the oar back. "You practice that motion over and over, usually alone," says Gevvie Stone, who will compete in single sculls in Rio. It helps that the drive to succeed on the water is in the Princeton grad's DNA: Her parents were Olympic rowers, and boat was her first word as a baby. Still, creating that poetic repetition on the water takes major muscle. She spends up to 90 minutes three times per week lifting weights. "You have to embrace the hurt," says Stone, a med school grad accustomed to chasing big dreams: She plans to become an orthopedic surgeon after the Olympics.

Her Moves

Lower-body strength is key for Stone, since her legs generate 70 percent of her power in rowing.

1. Reverse Lunge Stand with feet hip-width apart. Step left leg back into lunge, both knees bent 90 degrees. Push through front heel to return to start. Repeat on opposite side for 1 rep. Do 3 sets of 12 reps.

Candace Parker

Less than two years after surgery for an ACL tear, all 6 feet 4 inches of Candace Parker's sculpted body soared through the air and slammed the ball through the hoop. It wasn't just an epic display of physical strength and talent, it was the first dunk by a woman in an NCAA tournament game. A star forward in the WNBA, the two-time Olympic gold medalist has always had grit—and it's made her stronger after setbacks. Widely considered a shoo-in for the 2016 national team, Parker didn't make the roster. She was surprised but gracious, using Twitter to tell fans that all she can do is take things as they come. "I trust that everything happens for a reason," says the WNBA two-time MVP. "My focus now is the L.A. Sparks' season."

Her Moves

Parker credits band workouts for building the strength she uses to catch air during jump shots (and dunks!).

2. Kickback Start on hands and knees with band around right foot, secure under hands. Keep knee bent 90 degrees as you lift right leg so thigh is even with torso. Pause; return to start for 1 rep. Do 3 sets of 10 reps. Switch sides; repeat.

Simone Biles

"If I had to describe my gymnastics style in one word, it would be powerful," says Simone Biles, the teenage phenom who will join Team USA in Rio. Watch her masterfully executing a vault—her body launching sky-high for twists and somersaults, her muscular legs and rock-solid core helping her stick a flawless landing­—and it's clear: She's unstoppable. The three-time world all-around gymnastic champ sweats hard to be that good, spending an average of 32 hours a week at the gym. Though it will be her first Olympics, Biles is favored to win gold. Still, she's trying to keep the pressure to a minimum. "I'm so excited to meet the other athletes, to enjoy the journey," she says. "I'm ready to embrace this moment and have fun with it."

Her Moves

Core strength helps prevent wobbles and missteps. Biles uses these exercises to hit her abs from every angle.

1. Leg Lift Lie on back, palms facedown at sides. Inhale, then exhale as you slowly lift legs until they're perpendicular to floor. Lower to start for 1 rep. Do 3 sets of 10 reps.